1. Field of technology:
The invention concerns a method and a device to retrieve multimedia data.
2. Discussion of related art:
Driven by the digitalization in the consumer video, photo and audio market as well as by increasing capacity of re-writable storage devices such as hard discs and DVD, the enormous quantity of multimedia items and the problem of multimedia asset management is becoming much more important.
One of the challenges of multimedia asset management is to gather semantic information from the media in order to allow for easy data access. In the professional market, first products propose semantic access. For instance, temporal scenes in video are identified and allowing scene by scene video access. As another example, semantic elements in images such a “persons”, “indoor scenes” or “mountains” are identified. Videos and images can thus be searched and retrieved by semantic keywords. Web-based search engines for audio files use semantic information such as artist name and title to retrieve audio items.
One feature of multimedia item is its creation date and time, called in the following, creation date. The creation date is an important feature to retrieve multimedia items. For songs it indicates the creation period and gives hints to the music style. Further, creation date can be close to the moment where users have first heard the song. For videos, creation date is often close to date of first appearance in movie theatres or emission on television. Thus, the term creation date can be extended. It may be also the date of first presentation in a country by a specific medium or the date of its comeback into public interest. Creation date may mean also the date of reception of a multimedia item. For example, one receives some video clips from a server during Christmas holidays. Creation date could be the date of reception, since this is first time when the user consumes the multimedia item. Creation date may even be extended to usage tracking information such as access history.
The creation date is notably important for personal content. This type of content can be photos, video clips, audio clips, video films or other multimedia items that are produced or at least transformed at home by end users. User studies showed that creation date is one of the most important features for people to classify and retrieve their multimedia asset. Users often organize their multimedia items by creation date into directories. Search and retrieval is often done by remembering creation date and then retrieving the item by date.
The creation date has affective meaning to users. The creation of multimedia items is often linked to events in the personal life of users. Photos are often taken during holiday trips, family meetings or week-ends. Also video clips are often created during holidays or at specific moments such as weddings or at Christmas. In this way, multimedia items and their creation have a high emotional value to users. They form a mirror of memory of personal life.
One problem in managing multimedia assets is that the number of multimedia items is so large, and its organization is so coarse that users of multimedia assets forget, at least temporally, the existence of specific items. In case of anniversary of a specific event, users are often not aware of multimedia items that are linked to this event. The reason can be that they forgot their existence, or that the creator of a specific multimedia item was not himself but another person using the same multimedia asset. Thus it can be another person of the family that created, copied, bought or transformed a multimedia item linked to the event. Multimedia asset are often so large that even an asset management system would be too busy and don't have enough information to check at every moment the existence of item that could be interesting to a user in case of anniversary of an event.